1. Field of the Invention
The present invention relates to a meandering correction apparatus for an electrode assembly, and more particularly, a meandering correction apparatus for an electrode assembly, which aligns first and second unit cells, that are stacked in multiple stages in a stack/folding type electrode assembly, in the same direction to fix the first and second unit cells.
2. Description of the Related Art
In general, secondary batteries have attracted considerable attention as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs), which have been developed to solve limitations such as air pollution, caused by existing gasoline and diesel vehicles that use fossil fuels.
In such a secondary battery, a medium to large-scale electrode assembly in which a plurality of unit cells are connected to each other is being used because medium to large-scale devices such as vehicles require an high-output and high-capacity.
Here, the electrode assembly for the secondary battery may be classified into a jelly-roll type electrode assembly in which at least anode, separator, and cathode are successively stacked, a stack/folding type electrode assembly in which a unit cell including an anode, a separator, and a cathode, which are successively stacked, is disposed on a separator having a long film shape, and then the separator is wound in a single direction, and a stack/folding type electrode assembly in which a unit cell including an anode, a separator, and a cathode, which are successively stacked, is disposed on a separator having a long film shape, and then is wound in a zigzag direction.
The stack/folding type electrode assembly of the above-described electrode assemblies are disclosed in detail in Korean Patent Publication Nos. 2001-0082058, 2001-0082059, and 2001-0082060, which are filed by the present applicant.
The stack/folding type electrode assembly according to the related art, as illustrated in FIG. 1, may be manufactured in a stepped shape and thus built in miniaturized products.
That is, as illustrated in FIG. 2, in the stack/folding type electrode assembly according to the related art, first and second unit cells 10 and 20 having sizes different from each other are disposed on a separator 30 having a long film shape, and then the separator 30 is wound in a single direction.
However, referring to FIG. 2, in the stack/folding type electrode assembly according to the related art, the lowermost second unit cell 20 is wound in a state where the second unit cell 20 is disposed on an end of the separator 30 having the long film shape. Thus, the second unit cell 20 may have fixed one end and the unfixed other end to cause meandering due to a flow phenomenon of the second unit cell 20.